Test production from all three lines will commence during the first half of 2005, IBM said.

The three firms will together ramp up to an output capacity of 15,000 300mm wafers a month, Sony added.

Sony, IBM and Toshiba are jointly developing the 'Cell' microprocessor, expected to be used as the basis for Sony's PlayStation 3. IBM, meanwhile, is also working on the PowerPC-based CPU that will sit at the heart of Microsoft's Xbox 2 - aka Xbox Next - which will go head to head against the PS3.

Both consoles' CPUs are expected to be fabbed at 65nm. The investment is aimed specifically at gearing up for Cell's production.